Adjusting the pH of expired eosin dye by using either hydrocholic acid or glacial acetic acid to improve the efficiency of staining tissue.

Abstract

 This research work focused to study the improvement of expired eosin dye by using two types of acids. This dye is Eosin Y 1% aqueous solution that was commercial expired for 4 years. Eosin solution was divided into two groups that were tested with either hydrochloric acid (HCl) or Glacial acetic acid (GA) in different volume and pH. Acid quality of the first group was increased by using different volumes of HCl which were adjusted by 22.32 mM (pH~5.94), 44.64 mM (pH~5.74), 66.96 mM (pH~4.80), 111.61 mM (pH~2.13), 446.43 mM (pH~0.79) while acidity of the second group was adjusted by GA as 22.32 mM (pH~5.93), 111.61 mM (pH~5.23), 223.21 mM (pH~5.02), 446.43 mM (pH~4.59), 1,339.29 mM (pH~4.02), respectively. The control group used both new and old eosin dye. At low volume (22.32 mM), there was no significant difference on the quality of staining using HCl and GA. To compare the efficiency of both acids in higher volume and pH, the efficiency of intestine tissue's color staining was slightly changed little by using GA, whereas the more changing was revealed by using HCl. The efficient optimum range of HCl was 44.64-66.96 mM (pH~5.74-4.80), while the efficient range of GA was 446.43-1,339.29 mM (pH~4.59-4.02), compared with new control dye. The staining efficiency by using HCl should be careful because of rapid and strong impact in tissue. Therefore, this work will be useful to improve the efficiency of expired eosin dye by adjusting concentrations and pH of HCl and GA. (This work was supported by the grant from HRH Princess Mahachakri Sirindhorn Medical Center)